Japanese Giant Salamander

description

Ossification of the skull begins in phase II. The premaxilla, squamosal, dentary and columella begin to ossify. In some individuals, ossification of the vomer, parasphenoid and prearticular is also detected. An ossification centre is detected in the medial portion of the premaxilla, the anterior portion of the vomer and the posterolateral portion of the parasphenoid. The lateral part of the frontal and parietal bones begins to ossify along the anterior – posterior axis. In the pharynx, the hypohyal, ceratohyal, first and second hypobranchials and fourth ceratobranchial appear as cartilaginous structures. Ossification of the angular, coronoid and parietal begin in phases III and IV. The coronoid starts to ossify from the medial side and the parietal from the lateral side. In phase V, ossification of the maxilla, exoccipital and angular begins. The maxilla starts to ossify from the medial side, the exoccipital from the posterior side and the angular from the anterior side. Ossification of the premaxilla and dentary is advanced, and several teeth have developed on these bones. In phase VI, ossification begins at the medial side of the nasal, the lateral side of the frontal and the ant

Cranial skeletogenesis of one of the largest amphibians, Andrias japonicus, provides insight into ontogenetic adaptations for feeding in salamanders